Conversion of hydrocarbon oils



Patented Dec. 12, 1944 CONVERSION OF HYDROCARBON OILS Gerald G.Connolly, Baton Rouge, La... assignor to Standard Oil DevelopmentCompany, a corporation of Delaware No Drawing. Application October 31,1940,

Serial No. 363,701

2 Claims.

This invention relates to the conversion of hydrocarbon oils andpertains more particularly to the catalytic cracking of such oils. Theobject of the present invention is to use a catalyst for the cracking ofhydrocarbon oils which not only has a high activity but which canwithstand higher temperatures without becoming deactivated.

In an earlier filed application, serial No. 273,- 887, filed May 16,1939, I have described a catalyst for cracking hydrocarbon oilscomprising zirconium oxide and silica.

1 have now found that catalysts of this composition having a high orderof activity and having a higher heat stability, prepared as hereinafterdescribed, are useful in conversion of hydrocarbon oils.

In accordance with the present invention, I first impregnate the silica,preferably while in a hydrous state, with a zirconium salt solutioncapable of being chemically converted into zirconium oxide by treatmentwith a basic solution. The concentration of the zirconium salt solutionshould be such as to form a final product containingirom to zirconia byweight on the dry basis and preferably about 20%. The impregnation ofthe silica can be accomplished by soaking the same in a solution ofzirconium salt of required concentration to product a cata-.

lyst having the right concentration of zirconi oxide.

Following the impregnation the product is drained and may be eitherwashed and then dried or dried and then washed. In either event it isessential to subject the product to a washing treatment to produce acatalyst of maximum activity for catalytic cracking.

As previously mentioned, the silica which is impregnated with thezirconium salt is preferably in the form of a hydrous oxide, such as ahydrogel or gelatinous precipitate of silica. For best results, silicahydrogel is preferred. Such a hydrogel may be prepared, for instance,according to the general procedure outlined in the Patrick Patent No.1,297,724. When the procedure is carried out according to the disclosurebe a nitrate, sulfate or chloride. After the silica hydrogel has beenthoroughly impregnated with. the zirconium salt solution, the hydrogelis allowed to drain and is then treated to convert in this patent, aclear silica hydrosol first forms which upon standing sets into a firmjelly containing all of the water imbibed therein.

This product is then broken into lumps and thoroughly washed to removesoluble reaction products. The washed hydrogel is then soaked in asolution containing a zirconium salt until the hydrogel is thoroughlysaturated withsaid solution. The zirconium salt may, for example.

the salt into the oxide. An ammoniacal solution is preferred for thispurpose, although organic bases or other bases substantially free of thealkali metals may be used.

The resulting reaction mixture may then be washed and dried or dried andthen washed. The drying operation is'preferably carried. out atrelatively low temperature, such as below 212 until the bulk of thewater has been removed. from the silica hydrogel. Afterwards the productmay be activated by slowly heating to a temperature of 800 F. or aboveand maintaining said temperature for an extended period, such as from 3to 4 hours or more.

The resulting product may be used in granular, molded, or powdered formThe results obtained by the present invention are illustrated in thefollowing examples. It will be understood, however, that the values andconditions given in the examplesare illustrative rather than limitive.

In each of the examples given the activity of the catalyst for crackingoils was determined by passing an East Texas gas oil of 33.8 A. P. I.gravity in contact with the catalyst to be tested at a temperature of850 F. at a rate of .6 volume of liquid oil per volume of catalyst perhour and the average conversion into gasoline was determined over atwo-hour period.

Example 1 A silica hydrogel as described in Example 1 was impregnatedwith a zirconium nitrate solution of a concentration such as to form acatalyst containing about 20% of zirconium oxide. The

impregnated product was then treated with an ammoniacal solution toconvert the zirconium nitrate into-the oxide. This product was thendried. The dried product when tested under the above conditions resultedin a conversion of about 33% gasoline.

Example 3 Example 4 A catalyst was prepared as in Example 2, except thatfollowing the drying treatmentthc catalyst was washed before beingtested. This product resulted in the production of about 46.5% gasolineunder test conditions.

The catalysts prepared according tothe above description are not onlyextremely active for cracking hydrocarbon oils as shown above but are.also capable of being regenerated at high temperatures without impairingthe activity thereof.

Iclaim:

1. A method of cracking hydrocarbon oils which comprises passing the oilin vapor. form through a cracking zone containing a catalyst consistingessentially of silica and ziroonia prepared by first forming a silicahydrosol, thereafter caus il said hydrosol to coagulate into a hydrogel,removing reaction impurities from the hydrogel so formed, impregnatingthe washed silica hydrogel with a zirconium salt solution to form adried product containing from 15% to 25% of zirconium oxide, thereafterconverting the zirconium salt into the oxide, washing and drying theresulting product to form the catalyst, and maintaining the oil vaporswithin the cracking zone in contact with said catalyst for a periodsufllcient to convert a substantial portion thereof into motor fuelconstituents.

2. In the process defined by claim 1 wherein the zirconium salt istreated with an ammoniacal solution to convert the salt into the oxide.

GERALD q. CONNOLLY.

